Wearable device and method of controlling the same

ABSTRACT

A wearable device capable of synchronizing a plurality of wearable devices using body conductivity is provided. The wearable device includes a clock generator configured to generate a clock signal, a signal generator configured to generate a first synchronization signal based on the clock signal, an electrode configured to transmit and receive an electrical signal through a body while contacting the body, a switch configured to connect the signal generator and the electrode or block a connection between the signal generator and the electrode, and at least one processor configured to control the switch to connect the signal generator and the electrode for transmitting the first synchronization signal generated in the signal generator to the electrode in a master mode, and control the switch to block the connection between the signal generator and the electrode in a slave mode.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. §119(a) of a Korean patent application number 10-2020-0165540, filed onDec. 1, 2020, in the Korean Intellectual Property Office, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

The disclosure relates to a wearable device and a method of controllingthe same. More particularly, the disclosure relates to a wearable devicethat may transmit and receive a synchronization signal through a body.

2. Description of Related Art

A wearable device refers to all electronic devices worn on the body toperform computing activities.

Recently, much research on a hearable device capable of processing auser's voice signal or a sound signal around a user using a microphonemounted in a wearable device has been conducted.

When a user wears a plurality of hearable devices described above,synchronizing the plurality of hearable devices is required to providemore diverse functions.

However, when a radio frequency (RF) communication technology is usedfor simple time synchronization, a complexity of a circuit may becaused, which is inappropriate in terms of size and energy efficiency ofthe circuit.

Also, when a wearable device performs another function using the RFcommunication, the other function may be deteriorated.

In addition, a protocol of the RF communication may be embedded at anarbitrary time.

The above information is presented as background information only toassist with an understanding of the disclosure. No determination hasbeen made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentionedproblems and/or disadvantages and to provide at least the advantagesdescribed below. Accordingly, an aspect of the disclosure is to providea wearable device that may synchronize a plurality of wearable devicesusing body conductivity and a method of controlling the same.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

In accordance with an aspect of the disclosure, a wearable device isprovided. The device includes a clock generator configured to generate aclock signal, a signal generator configured to generate a firstsynchronization signal based on the clock signal, an electrodeconfigured to transmit and receive an electrical signal through a bodywhile contacting the body, a switch configured to connect the signalgenerator and the electrode or block a connection between the signalgenerator and the electrode, and at least one processor configured tocontrol the switch to connect the signal generator and the electrode fortransmitting the first synchronization signal generated in the signalgenerator to the electrode in a master mode, and control the switch toblock the connection between the signal generator and the electrode in aslave mode, wherein the at least one processor is further configured toadjust at least one of a frequency or a phase of the clock signal basedon a second synchronization signal received through the electrode fromanother wearable device worn on the body.

The at least one processor is configured to synchronize the firstsynchronization signal with the second synchronization signal byadjusting at least one of the frequency or the phase of the clocksignal.

The at least one processor is configured to determine an operation modeof the wearable device as the slave mode, based on a signal with aperiod greater than or equal to a predetermined value being receivedthrough the electrode.

The at least one processor is configured to determine an operation modeof the wearable device as the master mode, based on a signal with aperiod greater than or equal to a predetermined value not being receivedfor a predetermined period of time.

The at least one processor is configured to transmit a reset signal tothe signal generator in response to detecting a falling edge of thesecond synchronization signal.

The wearable device further includes a microphone, wherein the at leastone processor is configured to process a sound signal received from themicrophone based on the clock signal and the first synchronizationsignal.

The wearable device further includes a communicator configured towirelessly communicate with the other wearable device, wherein the atleast one processor is configured to perform beamforming based on thesound signal received from the microphone and a sound signal receivedfrom a second microphone of the other wearable device.

The wearable device further includes a communicator configured towirelessly communicate with an external terminal, wherein the at leastone processor is configured to process a sound signal received from theexternal terminal based on the clock signal and the firstsynchronization signal.

The at least one processor is configured to control the communicator totransmit the first synchronization signal to the external terminal.

The at least one processor is configured to control the switch to changean operation mode of the wearable device to the slave mode, based on thewearable device being operating in the master mode for a predeterminedperiod of time.

In accordance with another aspect of the disclosure, a method ofcontrolling a wearable device including an electrode that transmits andreceives an electrical signal through a body while contacting the bodyis provided. The method includes generating, by a clock generator, aclock signal, generating, by a signal generator, a first synchronizationsignal based on the clock signal, determining an operation mode of thewearable device, transmitting the first synchronization signal to theelectrode in response to determining the operation mode of the wearabledevice as a master mode, blocking a connection between the signalgenerator and the electrode in response to determining the operationmode of the wearable device as a slave mode, and adjusting at least oneof a frequency or a phase of the clock signal based on a secondsynchronization signal received through the electrode from anotherwearable device worn on the body, in the slave mode.

The adjusting of the at least one of the frequency or the phase of theclock signal includes synchronizing the first synchronization signalwith the second synchronization signal by adjusting at least one of thefrequency or the phase of the clock signal.

The determining of the operation mode of the wearable device includesdetermining the operation mode of the wearable device as the slave mode,based on a signal with a period greater than or equal to a predeterminedvalue being received through the electrode.

The determining of the operation mode of the wearable device includesdetermining the operation mode of the wearable device as the mastermode, based on a signal with a period greater than or equal to apredetermined value not being received for a predetermined period oftime.

The method further includes transmitting a reset signal to the signalgenerator in response to detecting a falling edge of the secondsynchronization signal.

The method further includes processing a sound signal received from amicrophone based on the clock signal and the first synchronizationsignal.

The method further includes wirelessly communicating with the otherwearable device and receiving a sound signal received from a secondmicrophone provided in the other wearable device, and performingbeamforming based on the sound signal received from the microphone andthe sound signal received from the second microphone.

The method further includes wirelessly communicating with an externalterminal and receiving a sound signal from the external terminal, andprocessing the sound signal received from the external terminal based onthe clock signal and the first synchronization signal.

The method further includes transmitting the first synchronizationsignal to the external terminal.

The method further includes changing the operation mode of the wearabledevice to the slave mode, based on the wearable device being operatingin the master mode for a predetermined period of time.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a diagram illustrating an example of a wearable deviceaccording to an embodiment of the disclosure;

FIG. 2 is a control block diagram illustrating a wearable deviceaccording to an embodiment of the disclosure;

FIG. 3 is a flowchart of a method of controlling a wearable deviceaccording to an embodiment of the disclosure;

FIG. 4 is a control block diagram illustrating a synchronization processbetween wearable devices according to an embodiment of the disclosure;

FIG. 5 illustrates a synchronization signal and a clock signal outputtedby wearable devices according to an embodiment of the disclosure; and

FIGS. 6 and 7 are flowcharts illustrating a method of controlling awearable device according to various embodiments of the disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thedisclosure. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of thedisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of thedisclosure is provided for illustration purpose only and not for thepurpose of limiting the disclosure as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

Terminologies used herein are for the purpose of describing particularembodiments only and is not intended to limit the disclosure.

It is to be understood that the singular forms are intended to includethe plural forms as well, unless the context clearly dictates otherwise.

It will be further understood that the terms “include”, “comprise”and/or “have” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms.

Further, the terms such as “part”, “device”, “block”, “member”,“module”, and the like may refer to a unit for processing at least onefunction or act. For example, the terms may refer to at least processprocessed by at least one hardware, such as field-programmable gatearray (FPGA)/application specific integrated circuit (ASIC), softwarestored in memories or processors.

Reference will now be made in detail to the embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout.

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings.

FIG. 1 is a diagram illustrating an example of a wearable deviceaccording to an embodiment of the disclosure.

Referring to FIG. 1 , the wearable device 1 according to an embodimentmay include one of a smart watch, a smart band, a smart ring, smartglasses or smart earphones (wireless earphones).

Further, the wearable device 1 according to an embodiment may includevarious types of devices such as a smart belt, smart shoes, smart socks,a smart shirt, smart pants, and the like.

That is, the wearable device 1 may refer to any electronic device thatmay be worn on a body, communicate with other wearable devices andperform computing activities.

Hereinafter, an example where the wearable device 1 is smart earphonesis described for convenience of explanation. More specifically, it isclarified that the wearable device 1 in the disclosure refers to oneside of the smart earphones, not a pair.

As shown in FIG. 1 , a user may wear a plurality of wearable devices,because a variety of wearable devices are being developed.

For instance, a user may wear the wearable device 1 on each of the leftand right ears, respectively.

Hereinafter, a circuit configuration of the wearable device 1 isdescribed below with reference to FIG. 2 .

FIG. 2 is a control block diagram illustrating a wearable deviceaccording to an embodiment of the disclosure.

Referring to FIG. 2 , according an embodiment, the wearable device 1 mayinclude an electrode 11, a switching element 12, a clock generator 14, asignal generator 15, a signal processor 16, a microphone 17, acommunicator 18, a speaker 19, and a controller 13. Here, one of theelements shown in FIG. 2 may be omitted according to an embodiment.

The electrode 11 may be provided at a position where the wearable device1 makes contact with a user's skin while worn on a body of a user.Therefore, the electrode 11 may be electrically connected to the user'sbody.

The electrode 11 may be electrically connected to another electrode incontact with the user's body through the user's body. Also, theelectrode 11 may transmit and receive an electrical signal to the otherelectrode in contact with the user's body.

That is, the electrode 11 may transmit and receive the electrical signalthrough the body while contacting the body.

Although not illustrated, the wearable device 1 may include at least onesensor that may output a sensing value to identify whether the wearabledevice 1 is worn on the body.

For example, the at least one sensor may include a current detectionsensor to output a sensing value according to whether the current canflow through the electrode 11, a capacitive sensor to detect acapacitance value that changes in response to the wearable device 1being worn on the body, and the like.

The clock generator 14 may include all circuits to generate a clocksignal clk for operating a variety of circuits included in the wearabledevice 1.

The clock signal clk may refer to a square wave signal where a logicstate high (high, 1) and low (low, 0) appear periodically, and be usedfor synchronization process that processes a signal in a digitalcircuit.

An element to define the clock signal clk may be a frequency, a dutyratio, a phase, etc.

For example, the clock generator 14 may be an oscillator that maygenerate the clock signal clk, and the oscillator may include a variablefrequency oscillator that may change an oscillation frequency.

The signal generator 15 may refer to all circuits that may generate asynchronization signal sync based on the clock signal clk. Thesynchronization signal sync may refer to all periodic signals generatedcorresponding to a period, a frequency, and the like of the clock signalclk.

For instance, the synchronization signal sync may refer to a signalobtained by converting a frequency and/or a duty ratio of the clocksignal clk. For example, a period of the synchronization signal sync maybe set to an integer multiple of the period of the clock signal clk.

The signal generator 15 for the above may include a counter circuit.

According to an embodiment, the signal generator 15 may receive a resetsignal, and be initialized in response to receiving the reset signal.

The signal processor 16 may process various types of signals based onthe clock signal clk outputted from the clock generator 14 and thesynchronization signal sync outputted from the signal generator 15.Specifically, the signal processor 16 may operate based on the clocksignal clk and the synchronization signal sync.

According to an embodiment, the signal processor 16 may process a soundsignal received from the microphone 17, and also process a sound signalreceived from the communicator 18.

The signal processor 16 may include at least one processor.

The sound signal processed by the signal processor 16 may be transmittedto an external terminal through the communicator 18, and be outputtedthrough the speaker 19.

The switching element 12 may selectively connect the signal generator 15and the electrode 11, or the signal generator 15 and the controller 13.

The switching element 12 may be operated based on a control signal ofthe controller 13.

The switching element 12 may include all switches capable of changing asignal path through an electric circuit by connecting or blocking theelectric circuit. For example, the switching element 12 may include aninsulated gate bipolar transistor (IGBT). Also, the number of switchingelements 12 may vary as needed.

The switching element 12 may transmit the synchronization signal sync,outputted from the signal generator 15, to the electrode 11 or thecontroller 13 according to the control signal of the controller 13.

The controller 13 may determine an operation mode of the wearable device1 based on an electrical signal received through the electrode 11. Also,the controller 13 may control the switching element 12 according to theoperation mode of the wearable device 1. Specifically, when a slave modeis determined as the operation mode of the wearable device 1, thecontroller 13 may control the switching element 12 so that thesynchronization signal sync outputted from the signal generator 15 istransmitted to the controller 13. When a master mode is determined asthe operation mode of the wearable device 1, the controller 13 maycontrol the switching element 12 so that the synchronization signal syncoutputted from the signal generator 15 is transmitted to the electrode11.

The controller 13 may transmit the reset signal to the signal generator15 based on the electrical signal received through the electrode 11.

Also, in the slave mode, the controller 13 may adjust at least one of afrequency or a phase of the clock signal clk based on the electricalsignal received through the electrode 11.

The controller 13 may include at least one processor and at least onememory.

The at least one memory may store a program and data for controlling theelements included in the wearable device 1, and memorize temporarycontrol data generated while controlling the elements include in thewearable device 1.

For instance, the at least one memory may include a program fordetermining the operation mode of the wearable device 1, a program forcontrolling the switching element 12 according to the operation mode ofthe wearable device 1, a program for adjusting the at least one of thefrequency or the phase of the clock signal clk generated from the clockgenerator 14, a program for transmitting the reset signal to the signalgenerator 15, and the like.

Here, the memory may include a non-volatile memory such as read onlymemory (ROM), flash memory, etc., for long-term storage of data, and avolatile memory such as static random access memory (S-RAM), dynamicrandom access memory (D-RAM), etc., for temporarily storing data.

The at least one processor included in the controller 13 may controleach element of the wearable device 1 according to the data and programstored in the at least one memory.

The at least one processor may include an arithmetic circuit thatperforms logical operations, arithmetic operations, etc., a memorycircuit that memorizes the calculated data, and the like.

For example, the at least one processor included in the controller 13may compare the synchronization signal sync, received from the signalgenerator 15, to a synchronization signal received from another wearabledevice through the electrode 11, and adjust the clock signal clkaccording to a result of the comparison in the slave mode.

As another example, the at least one processor included in thecontroller 13 may transmit the reset signal to the signal generator 15in response to detecting a falling edge of the synchronization signalreceived from the other wearable device through the electrode 11 in theslave mode.

An operation of the controller 13 is described in greater detail below.

The microphone 17 may collect ambient sound of the wearable device 1,and convert the collected sound into an electrical sound signal. Thesound signal collected by the microphone 17 may be processed by thesignal processor 16.

The communicator 18 may include a communication module for communicatingwith another terminal (e.g. a smart phone, another wearable device)including a short-range communication module and/or a wirelesscommunication module.

Specifically, the communicator 18 may include at least one communicationmodule transmitting and receiving data according to a predeterminedcommunication protocol. For instance, the communicator 18 may include awireless communication module and/or a short-range communication module.

The wireless communication module may include at least one ofcommunication modules capable of connecting to a wireless communicationnetwork by way of wireless communication, such as wireless fidelity(WiFi), wireless broadband (WiBro), global system for mobilecommunication (GSM), code division multiple access (CDMA), wideband codedivision multiple access (WCDMA), universal mobile telecommunicationssystem (UMTS), time division multiple access (TDMA), long term evolution(LTE), 4^(th) generation mobile communication, 5^(th) generation mobilecommunication, and the like.

The short-range communication module may include at least one ofcommunication modules capable of transmitting and receiving signalsusing a wireless communication network in a short distance, such asBluetooth module, infrared communication module, radio frequencyidentification (RFID) communication module, wireless local accessnetwork (WLAN) communication module, near field communication (NFC)communication module, zigbee communication module, Z-wave communicationmodule, wife direct communication module, Bluetooth low energy (BLE)module, and the like.

Also, the communicator 18 may include an antenna for transmitting orreceiving a wireless signal to or from free space, amodulator/demodulator for modulating data to be transmitted ordemodulating a received wireless signal, and the like.

The speaker 19 may convert a sound signal amplified by an audioamplifier into sound (sound wave). The audio amplifier may refer to anelement for amplifying the sound signal outputted from the signalprocessor 16.

The speaker 19 may include a thin film that vibrates according to anelectrical sound signal and sound waves may be generated by thevibration of the thin film.

For instance, the signal processor 16 may process a sound signalreceived from a smart phone through the communicator 18, the audioamplifier may amplify the sound signal processed by the signal processor16, and the speaker 19 may convert the amplified sound signal into soundand output the sound.

Each element of the wearable device 1 according to an embodiment hasbeen described above.

Hereinafter, a method of controlling the wearable device 1 is describedbelow with reference to FIGS. 3 to 5 .

FIG. 3 is a flowchart of a method of controlling a wearable deviceaccording to an embodiment of the disclosure. FIG. 4 is a control blockdiagram illustrating a synchronization process between wearable devicesaccording to an embodiment of the disclosure. FIG. 5 illustrates asynchronization signal and a clock signal outputted by wearable devicesaccording to an embodiment of the disclosure.

Hereinafter, for convenience of explanation, it is assumed that a userwears a plurality of wearable devices 1 according to an embodiment, andeach of the plurality of wearable devices 1 worn at different positionsis referred to as a first wearable device 10 and a second wearabledevice 20.

For example, the first wearable device 10 may be worn on one ear of theuser and the second wearable device 20 may be worn on the other ear ofthe user.

Referring to FIG. 4 , control block diagrams of the first wearabledevice 10 and the second wearable device 20 are illustrated.Hereinafter, it is assumed that both of the first wearable device 10 andthe second wearable device 20 are the wearable device 1 according to anembodiment.

Also, the following description is made based on the first wearabledevice 10 as the wearable device 1 operating in the master mode, and thesecond wearable device 20 as the wearable device 1 operating in theslave mode.

In addition, when power is applied to the first wearable device 10, aclock generator 140 may continuously generate a clock signal clk-1, andwhen power is applied to the second wearable device 20, a clockgenerator 240 may continuously generate a clock signal clk-2.

Referring to FIGS. 3 and 4 , a controller 130 may identify whether thefirst wearable device 10 is worn on a body of the user at operation1000. The above-described method may be used as a method of identifyingwhether the first wearable device 10 is worn on the body. For example,the controller 130 may identify whether the first wearable device 10 isworn on the body by detecting changes in capacitance value outputtedfrom a capacitive sensor.

As another example, the controller 130 may identify whether the firstwearable device 10 is worn on the body according to whether the currentcan flow through the electrode 11.

The controller 130 may determine an operation mode of the first wearabledevice 10 in response to the first wearable device 10 being worn on thebody at operation 1100.

Specifically, the controller 130 may determine the operation mode of thefirst wearable device 10 based on an electrical signal received throughthe electrode 11.

The operation mode may be divided into a master mode and a slave mode.The master mode may refer to a mode that serves as a synchronizationstandard for synchronizing the first wearable device 10 and anotherwearable device (e.g. the second wearable device 20) worn on the body.The slave mode may refer to a mode for the first wearable device 10 tobe synchronized based on a signal outputted from the second wearabledevice 20.

That is, when the first wearable device 10 operates in the master mode,the second wearable device 20 is synchronized based on a synchronizationsignal outputted from the first wearable device 10. When the firstwearable device 10 operates in the slave mode and the second wearabledevice 20 operates in the master mode, the first wearable device 10 issynchronized based on a synchronization signal outputted from the secondwearable device 20.

Based on a signal with a period greater than or equal to a predeterminedvalue being received through the electrode 11, the controller 130 maydetermine an operation mode of the wearable device as the slave mode.

The predetermined value may be set based on a period of a firstsynchronization signal sync-1 generated by a signal generator 150. Forinstance, with the assumption that the period of the firstsynchronization signal sync-1 is 1 ms, the predetermined value may beset to 0.8 ms which is shorter than the period of the firstsynchronization signal sync-1.

That is, the period of the predetermined value may refer to a periodshorter than the period of the first synchronization signal sync-1.

When the signal with the period greater than or equal to thepredetermined value is received through an electrode 110, it may beestimated that the signal is transmitted through an electrode 210 of thesecond wearable device 20 and an operation mode of the second wearabledevice 20 is the master mode.

As another example, when a signal with a period greater than or equal toa predetermined value is not received through the electrode 11 for apredetermined period of time, the controller 130 may determine anoperation mode of the first wearable device 10 as the master mode.

That is, when no signal is received through the electrode 11 even afterthe first wearable device 10 is worn on the body, it is estimated thatthe second wearable device 20 worn on the body in the master mode doesnot exist.

In this instance, the predetermined period of time may be set to aperiod of time longer than the period of the first synchronizationsignal sync-1 outputted from the signal generator 150.

When the first wearable device 10 and the second wearable device 20 aresimultaneously worn, both of the first wearable device 10 and the secondwearable device 20 may momentarily operate in the master mode. In thisinstance, the first synchronization signal sync-1 transmitted throughthe electrode 110 of the first wearable device 10 and the secondsynchronization signal sync-2 transmitted through the electrode 210 ofthe second wearable device 20 may collide with each other. To preventthe above collision, a multiple access with collision avoidance (MACA)may be used.

Specifically, when the first wearable device 10 operating in the mastermode transmits the first synchronization signal sync-1 through theelectrode 110 and receives the second synchronization signal sync-2through the electrode 110 from the second wearable device 20, thecontroller 130 may control a switching element 120 to temporarily blocka connection between the signal generator 150 and the electrode 110.

Even after temporary blocking of the connection between the signalgenerator 150 and the electrode 110, when the second synchronizationsignal sync-2 is continuously received through the electrode 110 fromthe second wearable device 20, the controller 130 may determine theoperation mode of the first wearable device 10 as the slave mode.

When the operation mode of the first wearable device 10 is determined asthe master mode (Yes in operation 1200), the controller 130 may controlthe switching element 120 to transmit the first synchronization signalsync-1 outputted from the signal generator 150 to the electrode 110 atoperation 1250.

That is, in response to determining the operation mode of the firstwearable device 10 as the master mode, the first wearable device 10 maytransmit the first synchronization signal sync-1 to another wearabledevice 1, worn on the body (Human Body), through the electrode 110, andthe electrode 210 of the second wearable device 20 may receive the firstsynchronization signal sync-1, outputted from the signal generator 150,through the body (HB).

A frequency of the first synchronization signal sync-1 may be set inadvance and be set to 20 MHz or more considering conduction efficiencyin the body.

Hereinafter, operations of synchronization based on the firstsynchronization signal sync-1 outputted from the signal generator 150,when the second wearable device 20 operates in the slave mode, aredescribed.

As described above, a controller 230 may detect whether the secondwearable device 20 is worn on the body of the user at operation 1000.Also, the controller 230 may determine the operation mode of the secondwearable device 20 at operation 1100.

In response to determining the operation mode of the second wearabledevice 20 as the slave mode (No in operation 1200), the controller 230may control a switching element 220 to block a connection between asignal generator 250 and the electrode 210 at operation 1300.

More specifically, the controller 230 may control the switching element220 not to transmit the second synchronization signal sync-2 to theelectrode 210 in the slave mode of the second wearable device 20. Here,the second synchronization signal sync-2 is outputted from the signalgenerator 250.

Also, the controller 230 may control the switching element 220 totransmit the second synchronization signal sync-2, outputted from thesignal generator 250, to the controller 230.

When the operation mode of the second wearable device 20 is the slavemode, the first synchronization signal sync-1, transmitted through theelectrode 110 of the first wearable device 10 operating in the mastermode, may be received in the electrode 210 of the second wearable device20 through the body (HB), and the controller 230 may receive the firstsynchronization signal sync-1 through the electrode 210.

That is, the controller 230 may receive both of the firstsynchronization signal sync-1, outputted from the signal generator 150of the first wearable device 10, and the second synchronization signalsync-2 outputted from the signal generator 250 of the second wearabledevice 20.

The controller 230 may compare the first synchronization signal sync-1and the second synchronization signal sync-2 at operation 1400. Also,the controller 230 may adjust the clock signal clk-2 according to aresult of the comparison at operation 1500.

Specifically, the controller 230 may adjust at least one of a frequencyor a phase of the clock signal clk-2 generated by the clock generator240 based on the first synchronization signal sync-1 and the secondsynchronization signal sync-2.

For example, the controller 230 may synchronize the firstsynchronization signal sync-1 and the second synchronization signalsync-2 by adjusting at least one of the frequency or the phase of theclock signal clk-2 generated by the clock generator 240.

According to an embodiment, the controller 230 may transmit a resetsignal to the signal generator 250 in response to detecting a fallingedge of the first synchronization signal sync-1, to more preciselycompare the first synchronization signal sync-1 and the secondsynchronization signal sync-2.

The falling edge of the first synchronization signal sync-1 may refer toa point in time when a pattern of the first synchronization signalsync-1 ends. Also, when the controller 230 resets the signal generator250 using the detection of the falling edge, the first synchronizationsignal sync-1 may be precisely compared to the second synchronizationsignal sync-2 generated corresponding to the adjusted clock signalclk-2.

Referring to FIG. 5 , a synchronization process of the firstsynchronization signal sync-1 and the second synchronization signalsync-2 is illustrated.

Based on a reset signal, in a first section T1, a phase of the firstsynchronization signal sync-1 precedes that of the secondsynchronization signal sync-2.

The controller 230 may control the clock generator 240 to delay thephase of the clock signal clk-2 based on the result that the phase ofthe first synchronization signal sync-1 precedes that of the secondsynchronization signal sync-2.

In a second section T2, the phase of the second synchronization signalsync-2, generated based on the adjusted clock signal clk-2, precedesthat of the first synchronization signal sync-1.

Accordingly, the controller 230 may control the clock generator 240 todelay the phase of the clock signal clk-2.

Through the synchronization process described above, the firstsynchronization signal sync-1 and the second synchronization signalsync-2 may be synchronized.

The controller 230 may identify that the synchronization process iscomplete in response to the first synchronization signal sync-1 and thesecond synchronization signal sync-2 being matched.

According to another embodiment, to more precisely compare the firstsynchronization signal sync-1 and the second synchronization signalsync-2, the controller 230 may transmit a reset signal to the signalgenerator 250 in response to detecting a rising edge of the firstsynchronization signal sync-1.

According to an embodiment of the disclosure, the wearable devices 1worn on the body may be easily synchronized without using communicationtechnologies such as Bluetooth, WiFi, body area network (BAN), etc., andthus disadvantages of the related art may be overcome.

Although not illustrated in drawings, when the wearable device 1operates in the master mode for a predetermined period of time, thecontroller 13 may control the switching element 12 to convert theoperation mode of the wearable device 1 to the salve mode consideringbattery consumption.

That is, when the first wearable device 10 operates in the master modefor a first predetermined period of time, the controller 130 may controlthe switching element 120 to block a connection between the signalgenerator 150 and the electrode 110. Also, the controller 230 mayconvert the operation mode of the second wearable device 20 to themaster mode in response to not receiving the first synchronizationsignal sync-1 through the electrode 210 for a second predeterminedperiod of time.

In response to the synchronization of the first wearable device 10 andthe second wearable device 20, the first wearable device 10 and thesecond wearable device 20 may perform various functions based on thesynchronization.

FIGS. 6 and 7 are flowcharts illustrating a method of controlling awearable device according to various embodiments of the disclosure.

According to another embodiment, the first wearable device 10 and thesecond wearable device 20 may perform beamforming using microphones 170and 270. Each of the microphones 170 and 270 is provided in each of thefirst wearable device 10 and the second wearable device 20.

Referring to FIG. 6 in view of the first wearable device 10, the firstwearable device 10 may identify whether synchronization is complete atoperation 2000.

For instance, when synchronization of the second wearable device 20 isidentified to be completed, the controller 230 of the second wearabledevice 20 may control the communicator 280 to transmit a synchronizationcompletion message to the first wearable device 10. Also, thecommunicator 180 of the first wearable device 10 may receive thesynchronization completion message from the communicator 280 of thesecond wearable device 20.

The controller 130 may identify that the synchronization of the secondwearable device 20 is complete, in response to receiving thesynchronization completion message received from the communicator 180.

In response to the completion of the synchronization of the secondwearable device 20, the controller 130 may control the communicator 180to receive a sound signal received from the microphone 270 of the secondwearable device 20.

Specifically, the controller 130 may control the communicator 180 totransmit a message requesting transmission of the sound signal to thesecond wearable device 20. Also, in response to receiving the messagethrough the communicator 280, the controller 230 of the second wearabledevice 20 may control the communicator 280 to transmit the sound signal,received from the microphone 270, to the first wearable device 10.

In this instance, the sound signal received through the microphone 270may refer to a sound signal processed by a signal processor 260 atoperation 2100.

The signal processor 160 may perform beamforming based on the soundsignal received from the microphone 170 of the first wearable device 10and the sound signal received from the microphone 270 of the secondwearable device 20 at operation 2200.

That is, because the first wearable device 10 and the second wearabledevice 20 are completely synchronized, a location of a sound source maybe identified by processing the sound signal received from themicrophone 170 of the first wearable device 10 and the sound signalreceived from the microphone 270 of the second wearable device 20.

Referring to FIG. 6 in view of the second wearable device 20, the secondwearable device 20 may identify whether synchronization is complete atoperation 2000.

For instance, the controller 230 of the second wearable device 20 mayidentify whether synchronization is complete based on a result ofcomparing the first synchronization signal sync-1 and the secondsynchronization signal sync-2.

In response to the completion of synchronization of the second wearabledevice 20, the controller 230 may control the communicator 280 toreceive a sound signal received from the microphone 170 of the firstwearable device 10.

Specifically, the controller 230 may control the communicator 280 totransmit a message requesting transmission of the sound signal to thefirst wearable device 10. Also, in response to receiving the messagethrough the communicator 180, the controller 130 of the first wearabledevice 10 may control the communicator 180 to transmit the sound signal,received from the microphone 170, to the second wearable device 20.

In this instance, the sound signal received from the microphone 170 mayrefer to a sound signal processed by the signal processor 160 atoperation 2100.

The signal processor 260 may perform beamforming based on the soundsignal received from the microphone 170 of the first wearable device 10and the sound signal received from the microphone 270 of the secondwearable device 20 at operation 2200.

According to another embodiment, the wearable device 1 may receive, froman external terminal, a sound signal whose phase is corrected accordingto a synchronization signal.

Referring to FIG. 7 in view of the first wearable device 10, when thefirst wearable device 10 and the second wearable device 20 aresynchronized at operation 3000, the first wearable device 10 maytransmit the first synchronization signal sync-1 to the externalterminal, e.g. a smart phone at operation 3100.

That is, the controller 130 may control the communicator 180 to transmitthe first synchronization signal sync-1 outputted from the signalgenerator 150 to the external terminal.

Accordingly, the external terminal may correct a phase of streamingsound signal based on the first synchronization signal sync-1, andtransmit the corrected sound signal to the first wearable device 10 andthe second wearable device 20.

The first wearable device 10 may receive the sound signal from theexternal terminal through the communicator 180 at operation 3200. Also,the signal processor 160 may process the sound signal received from theexternal terminal based on the first synchronization signal sync-1 andthe clock signal clk-1.

In addition, the sound signal processed by the signal processor 160 maybe outputted in a form of sound wave through a speaker 190 at operation3300.

Referring to FIG. 7 in view of the second wearable device 20, when thesecond wearable device 20 and the first wearable device 10 aresynchronized at operation 3000, the second wearable device 20 maytransmit the second synchronization signal sync-2 to an externalterminal, e.g. a smart phone at operation 3100.

That is, the controller 230 may control the communicator 280 to transmitthe second synchronization signal sync-2 outputted from the signalgenerator 250 to the external terminal.

Accordingly, the external terminal may correct a phase of streamingsound signal based on the second synchronization signal sync-2, andtransmit the corrected sound signal to the first wearable device 10 andthe second wearable device 20.

The second wearable device 20 may receive the sound signal from theexternal terminal through the communicator 280 at operation 3200. Also,the signal processor 260 may process the sound signal received from theexternal terminal based on the second synchronization signal sync-2 andthe clock signal clk-2.

In addition, the sound signal processed by the signal processor 260 maybe outputted in a form of sound wave through a speaker 290 at operation3300.

According to embodiments of the disclosure, precise soundsynchronization can be achieved among the wearable devices which are notdirectly connected to each other in a playback mode.

As is apparent from the above, according to the embodiment of thedisclosure, the wearable device and the method of controlling the samecan provide more diverse functions, e.g. beamforming, to a user byeasily synchronizing the wearable devices worn by the user.

Further, the wearable device and the method of controlling the same cansynchronize the wearable devices using a simple circuit without usingwireless communication technology.

Embodiments can thus be implemented through computer readablecode/instructions in/on a medium, e.g., a computer readable medium, tocontrol at least one processing element to implement any above describedembodiment. The medium can correspond to any medium/media permitting thestoring and/or transmission of the computer readable code.

The computer-readable code can be recorded on a medium or transmittedthrough the Internet. The medium may include Read Only Memory (ROM),Random Access Memory (RAM), magnetic tapes, magnetic disks, floppydisks, and optical recording medium.

The computer-readable code may be provided in the form of anon-transitory storage medium. Here, when a storage medium is referredto as “non-transitory”, it can be understood that the storage medium istangible and does not include a signal, but rather that data issemi-permanently or temporarily stored in the storage medium.

According to one embodiment, the methods according to the variousembodiments disclosed herein may be provided in a computer programproduct. The computer program product may be traded between a seller anda buyer as a product. The computer program product may be distributed inthe form of a machine-readable storage medium (e.g., compact disc readonly memory (CD-ROM)), or may be distributed through an applicationstore (e.g., Play Store TM) online. In the case of online distribution,at least a portion of the computer program product (e.g., downloadableapp) may be stored at least temporarily or may be temporarily generatedin a machine-readable storage medium, such as a memory of a server of amanufacturer, a server of an application store, or a relay server.

While the disclosure has been shown and described with reference tovarious embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the disclosure as definedby the appended claims and their equivalents.

What is claimed is:
 1. A wearable device comprising: a clock generatorconfigured to generate a clock signal; a signal generator configured togenerate a first synchronization signal based on the clock signal; anelectrode configured to transmit and receive an electrical signalthrough a body while contacting the body; a switch configured to connectthe signal generator and the electrode or block a connection between thesignal generator and the electrode; and at least one processorconfigured to: control the switch to connect the signal generator andthe electrode for transmitting the first synchronization signalgenerated in the signal generator to the electrode in a master mode, andcontrol the switch to block the connection between the signal generatorand the electrode in a slave mode, wherein the at least one processor isfurther configured to adjust at least one of a frequency or a phase ofthe clock signal based on a second synchronization signal receivedthrough the electrode from another wearable device worn on the body. 2.The wearable device of claim 1, wherein the at least one processor isfurther configured to synchronize the first synchronization signal withthe second synchronization signal by adjusting at least one of thefrequency or the phase of the clock signal.
 3. The wearable device ofclaim 1, wherein the at least one processor is further configured todetermine an operation mode of the wearable device as the slave mode,based on a signal with a period greater than or equal to a predeterminedvalue being received through the electrode.
 4. The wearable device ofclaim 1, wherein the at least one processor is further configured todetermine an operation mode of the wearable device as the master mode,based on a signal with a period greater than or equal to a predeterminedvalue not being received for a predetermined period of time.
 5. Thewearable device of claim 1, wherein the at least one processor isfurther configured to transmit a reset signal to the signal generator inresponse to detecting a falling edge of the second synchronizationsignal.
 6. The wearable device of claim 1, further comprising: amicrophone, wherein the at least one processor is further configured toprocess a sound signal received from the microphone based on the clocksignal and the first synchronization signal.
 7. The wearable device ofclaim 6, further comprising: a communicator configured to wirelesslycommunicate with the other wearable device, wherein the at least oneprocessor is further configured to perform beamforming based on thesound signal received from the microphone and a sound signal receivedfrom a second microphone of the other wearable device.
 8. The wearabledevice of claim 1, further comprising: a communicator configured towirelessly communicate with an external terminal, wherein the at leastone processor is further configured to process a sound signal receivedfrom the external terminal based on the clock signal and the firstsynchronization signal.
 9. The wearable device of claim 8, wherein theat least one processor is further configured to control the communicatorto transmit the first synchronization signal to the external terminal.10. The wearable device of claim 1, wherein the at least one processoris further configured to control the switch to change an operation modeof the wearable device to the slave mode, based on the wearable devicebeing operating in the master mode for a predetermined period of time.11. A method of controlling a wearable device including an electrodethat transmits and receives an electrical signal through a body whilecontacting the body, the method comprising: generating, by a clockgenerator, a clock signal; generating, by a signal generator, a firstsynchronization signal based on the clock signal; determining anoperation mode of the wearable device; transmitting the firstsynchronization signal to the electrode in response to determining theoperation mode of the wearable device as a master mode; blocking aconnection between the signal generator and the electrode in response todetermining the operation mode of the wearable device as a slave mode;and adjusting at least one of a frequency or a phase of the clock signalbased on a second synchronization signal received through the electrodefrom another wearable device worn on the body, in the slave mode. 12.The method of claim 11, wherein the adjusting of the at least one of thefrequency or the phase of the clock signal comprises: synchronizing thefirst synchronization signal with the second synchronization signal byadjusting at least one of the frequency or the phase of the clocksignal.
 13. The method of claim 11, wherein the determining of theoperation mode of the wearable device comprises: determining theoperation mode of the wearable device as the slave mode, based on asignal with a period greater than or equal to a predetermined valuebeing received through the electrode.
 14. The method of claim 11,wherein the determining of the operation mode of the wearable devicecomprises: determining the operation mode of the wearable device as themaster mode, based on a signal with a period greater than or equal to apredetermined value not being received for a predetermined period oftime.
 15. The method of claim 11, further comprising: transmitting areset signal to the signal generator in response to detecting a fallingedge of the second synchronization signal.
 16. The method of claim 11,further comprising: processing a sound signal received from a microphonebased on the clock signal and the first synchronization signal.
 17. Themethod of claim 16, further comprising: wirelessly communicating withthe other wearable device and receiving a sound signal received from asecond microphone provided in the other wearable device; and performingbeamforming based on the sound signal received from the microphone andthe sound signal received from the second microphone.
 18. The method ofclaim 11, further comprising: wirelessly communicating with an externalterminal and receiving a sound signal from the external terminal; andprocessing the sound signal received from the external terminal based onthe clock signal and the first synchronization signal.
 19. The method ofclaim 18, further comprising: transmitting the first synchronizationsignal to the external terminal.
 20. The method of claim 11, furthercomprising: changing the operation mode of the wearable device to theslave mode, based on the wearable device being operating in the mastermode for a predetermined period of time.